Optical scanning or laser scanning describes the controlled pointing (steering) of a light path or laser beam with at least one axis of motion. Two-axis scanning assemblies enable a laser beam to be projected onto a large two dimensional plane with very fast response times related to motion along the axes. Assemblies that steer laser beams may be used in a wide array of industries including additive manufacturing, material processing, laser engraving, optometry, cosmetology, confocal microscopy, laser shows, computer games, LIDAR, barcode scanners, and measuring three dimensional objects for a wide variety of applications.
Laser scanners using galvanometers to rotate mirrors are often utilized to provide such two-axis scanning assemblies. While galvanometer scanners are readily available commercially, galvanometer scanners are generally large assemblies that require high-power electronics with significant heat sinking capabilities. One commercial example of a galvanometer scanner provides a two-axis orthogonal mirror scanner. The scanner accepts up to a 5 mm diameter laser beam and has a range of motion of +/−12.5 degrees. The motor and mirror scanning head is 61×61×36 mm and the separate drive and control electronics are 85×74×84 mm, such that the total volume of the scanner system is nearly 600 cubic centimeters. Such a scanner is too large for many applications and requires high power electronics.
Recent advancements in MEMS technology have demonstrated optical scanning mirrors that are significantly smaller than galvanometer scanners. These scanners, however, still require separate, and relatively large, electronics to provide voltage driving signals that are many hundreds of volts. Thus, these scanners, in view of the size of the electronics required and the amount of power consumed, are also limited with respect to the applications to which they may be applied.